Human and veterinary hospitals, surgical clinics, pathology laboratories and associated health care facilities throughout the world are routinely removing and disposing of tissues and body fluids from sick, injured and frequently infected humans and animals. In addition, large volumes of contaminated syringes, tubes, surgical bandages and blood products enter the waste streams of these institutions. In many cases, these materials are harmless and pose no threat of infection to persons who handle or who are otherwise exposed to them. In some cases, however, these materials can contain infective viruses, pathogenic bacteria, toxins and/or bacterial spores which constitute a threat to patients, health care professionals and the general public. In many cases, hospital and clinical waste carries with it a noxious odor and may be considered unsightly.
In addition to the above-mentioned facilities, there are numerous university and medical school facilities in which research into the etiology of disease, experimental therapeutics and basic research is conducted. Fermentation broths and tissue cultures, as well as experimental animals, may frequently contain higher concentrations of rare and pathogenic organisms and toxic and carcinogenic chemical agents than would be found in hospital and clinical wastes. Agricultural research facilities frequently produce mosses, ferns and fungi which reproduce through sporulation and which may be either pathogenic or allergenic.
Recent advances in genetic engineering enable the production of potent pharmaceuticals, toxins, and other biochemicals in large fermentation cultures. Once the desired chemical products have been isolated from the broth, the broth must be properly treated to control both odor and the possibility that potentially infectious agents and toxins may be released into the environment.
The disposal of small amounts of infectious laboratory wastes, bandages and similar contaminated materials has, since the invention of the Chamberland autoclave in 1884, been performed using wet steam. Wet steam is effective against most bacteria and mycotoxins, but is frequently ineffective against spores, toxins and the so-called "slow" viruses. Steam sterilization is extremely energy intensive, must be monitored regularly for effectiveness, usually produces an odiferous product, and results in no dimunition in the size of the waste. The autoclaving of whole research animals and large volumes of tissue is rarely practiced, except in extreme emergencies.
Chemical treatment of pathological waste has never achieved routine use. Chemical treatment of tissues requires the handling of comparatively large volumes of corrosive and toxic chemicals, such as chloride of lime and formaldehyde. The end result is an increased volume of a sterile, albeit chemically hazardous, waste.
The incineration of whole bodies, parts thereof and tissues has been a routine procedure at medical facilities, morgues, mortuaries and veterinary hospitals. Incineration involves minimum transportation within and especially outside of the institution, produces a small volume of essentially sterile waste, and is comparatively energy efficient. Since the passage of the Hill-Burton Act, all hospitals constructed using federal funds have been required to install a pathological incinerator. Air quality regulations emanating from Federal Environmental Protection Agency and from state equivalents place limits upon the visible emissions from such incinerators. Because retrofitting of this equipment frequently entails major design changes, particularly with older equipment, many of these incinerators have been phased out. The use of small, pathological incinerators for the disposal of laboratory wastes and patient contact items is limited by the design of a pathological incinerator, which is typically a small solid hearth, single chamber unit. The incineration of significant volumes of plastic laboratory items such as petri dishes and syringes results in the emmission of large quantities of black smoke, and the BTU content of these items frequently causes dramatic changes in combustion chamber temperatures. The incorporation of tissue and infectious waste into the general waste stream of an institution has been attempted at several large medical institutions, but entails the installation of new and complex incinerators and the hiring of additional, qualified operators, and is frequently beyond the financial capabilities of small and medium sized hospitals.
There exists, therefore, a need for a device capable of destroying pathogenic organisms, spores and viruses, as well as the tissues and laboratory equipment in which they are contained, which device is capable of significantly reducing the volume of waste while producing gaseous and particulate emissions of low toxicity or which are easily trapped or otherwise contained. The device should be amenable to production in sizes suitable for installation in facilities zoned for light industry and require minimum operator training and service. Finally, the cost of construction and operation must be competitive with other, less efficient, methods of disposal.